vismach.py new hal pin vismach.plotclear

The pin can be accessed by virtual control panels (like pyvcp)
or with sim_pin. Example:

$ sim_pin vismach.plotclear/mode=Pulse

Author: dngarrett

docs/src/getting-started/updating-linuxcnc.txt

@@ -1252,6 +1252,8 @@ a user-customized homing.c file.
 lib/hallib/sim_lib.tcL: simulate encoder index if [JOINT_n]HOME_USE_INDEX
 is specified.
 
+lib/python/vismach.py: new hal pin vismach.plotclear
+
 === Hal
 
 ==== Components

lib/python/vismach.py

@@ -18,6 +18,7 @@
 from minigl import *
 from math import *
 import glnav
+import hal
 
 class Collection(object):
     def __init__(self, parts):
@@ -880,6 +881,9 @@ def redraw(self, *args):
 	# back to world again
 	glPopMatrix()
 
+    def plotclear(self):
+        del self.plotdata[:self.plotlen]
+
 class Color(Collection):
     def __init__(self, color, parts):
         self.color = color
@@ -999,6 +1003,8 @@ def draw(self):
         glCallList(self.list)
 
 
+old_plotclear = False
+
 def main(model, tool, work, size=10, hud=0, rotation_vectors=None, lat=0, lon=0):
     app = Tkinter.Tk()
 
@@ -1010,6 +1016,10 @@ def main(model, tool, work, size=10, hud=0, rotation_vectors=None, lat=0, lon=0)
     # set starting viewpoint if desired
     t.after(100, lambda: t.set_viewangle(lat, lon))
 
+    vcomp = hal.component("vismach")
+    vcomp.newpin("plotclear",hal.HAL_BIT,hal.HAL_IN)
+    vcomp.ready()
+
     #there's probably a better way of doing this
     global HUD
     HUD = 0
@@ -1034,7 +1044,12 @@ def main(model, tool, work, size=10, hud=0, rotation_vectors=None, lat=0, lon=0)
     t.pack(fill="both", expand=1)
 
     def update():
+	global old_plotclear
 	t.tkRedraw()
+	new_plotclear = vcomp["plotclear"]
+	if new_plotclear and not old_plotclear:
+	    t.plotclear()
+	old_plotclear=new_plotclear
 	t.after(100, update)
     update()